ETL service sampling has encountered an error, ERROR: more than one row returned by a subquery used as an expression in RHV 4.1

Issue

• There are multiple errors in RHV GUI:

ETL service sampling has encountered an error

• In the /var/log/ovirt-engine-dwh/ovirt-engine-dwhd.log, following messages were observed:

2017-11-16 11:58:54|ETL Service Started
ovirtEngineDbDriverClass|org.postgresql.Driver
ovirtEngineHistoryDbJdbcConnection|jdbc:postgresql://localhost:5432/ovirt_engine_history?sslfactory=org.postgresql.ssl.NonValidatingFactory
hoursToKeepDaily|0
hoursToKeepHourly|720
ovirtEngineDbPassword|******************
runDeleteTime|3
ovirtEngineDbJdbcConnection|jdbc:postgresql://localhost:5432/engine?sslfactory=org.postgresql.ssl.NonValidatingFactory
runInterleave|20
limitRows|limit 1000
ovirtEngineHistoryDbUser|ovirt_engine_history
ovirtEngineDbUser|engine
deleteIncrement|10
timeBetweenErrorEvents|300000
hoursToKeepSamples|24
deleteMultiplier|1000
lastErrorSent|2011-07-03 12:46:47.000000
etlVersion|4.1.1
dwhAggregationDebug|false
dwhUuid|<uuid>
ovirtEngineHistoryDbDriverClass|org.postgresql.Driver
ovirtEngineHistoryDbPassword|*******************
Exception in component tJDBCInput_9
org.postgresql.util.PSQLException: ERROR: more than one row returned by a subquery used as an expression
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2157)
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1886)
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:555)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:403)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:283)
    at ovirt_engine_dwh.configurationsync_4_1.ConfigurationSync.tJDBCInput_9Process(ConfigurationSync.java:3727)
    at ovirt_engine_dwh.configurationsync_4_1.ConfigurationSync$2.run(ConfigurationSync.java:60001)
2017-11-16 11:59:00|tq8eIV|u4tAVT|bDaPTQ|OVIRT_ENGINE_DWH|ConfigurationSync|Default|6|Java Exception|tJDBCInput_9|org.postgresql.util.PSQLException:ERROR: more than one row returned by a subquery used as an expression|1
Exception in component tRunJob_1
java.lang.RuntimeException: Child job running failed
    at ovirt_engine_dwh.samplerunjobs_4_1.SampleRunJobs.tRunJob_1Process(SampleRunJobs.java:1198)
    at ovirt_engine_dwh.samplerunjobs_4_1.SampleRunJobs.tRunJob_4Process(SampleRunJobs.java:1000)
    at ovirt_engine_dwh.samplerunjobs_4_1.SampleRunJobs.tJDBCConnection_2Process(SampleRunJobs.java:767)
    at ovirt_engine_dwh.samplerunjobs_4_1.SampleRunJobs.tJDBCConnection_1Process(SampleRunJobs.java:642)
    at ovirt_engine_dwh.samplerunjobs_4_1.SampleRunJobs$2.run(SampleRunJobs.java:2683)
2017-11-16 11:59:00|bDaPTQ|u4tAVT|er3dxX|OVIRT_ENGINE_DWH|SampleRunJobs|Default|6|Java Exception|tRunJob_1|java.lang.RuntimeException:Child job running failed|1
Exception in component tRunJob_1
java.lang.RuntimeException: Child job running failed
    at ovirt_engine_dwh.sampletimekeepingjob_4_1.SampleTimeKeepingJob.tRunJob_1Process(SampleTimeKeepingJob.java:6067)
    at ovirt_engine_dwh.sampletimekeepingjob_4_1.SampleTimeKeepingJob.tJDBCInput_2Process(SampleTimeKeepingJob.java:5809)
    at ovirt_engine_dwh.sampletimekeepingjob_4_1.SampleTimeKeepingJob.tJDBCConnection_1Process(SampleTimeKeepingJob.java:4444)
    at ovirt_engine_dwh.sampletimekeepingjob_4_1.SampleTimeKeepingJob.tJDBCConnection_2Process(SampleTimeKeepingJob.java:4319)
    at ovirt_engine_dwh.sampletimekeepingjob_4_1.SampleTimeKeepingJob.tRowGenerator_2Process(SampleTimeKeepingJob.java:4188)
    at ovirt_engine_dwh.sampletimekeepingjob_4_1.SampleTimeKeepingJob.tJDBCInput_3Process(SampleTimeKeepingJob.java:3593)
    at ovirt_engine_dwh.sampletimekeepingjob_4_1.SampleTimeKeepingJob.tJDBCInput_5Process(SampleTimeKeepingJob.java:2977)
    at ovirt_engine_dwh.sampletimekeepingjob_4_1.SampleTimeKeepingJob.tJDBCInput_4Process(SampleTimeKeepingJob.java:2295)
    at ovirt_engine_dwh.sampletimekeepingjob_4_1.SampleTimeKeepingJob.tJDBCConnection_3Process(SampleTimeKeepingJob.java:1649)
    at ovirt_engine_dwh.sampletimekeepingjob_4_1.SampleTimeKeepingJob$2.run(SampleTimeKeepingJob.java:11363)